By Choi Sung-jinPresident Moon Jae-in's four-day state visit to China last week has left some points to ponder about good diplomacy. The rival political parties disagree on most issues, but their assessments of Moon's China visit couldn't be more of a contrast. The ruling Democratic Party of Korea praised it as a breakthrough that restored the bilateral relationship strained by South Korea's deployment of a U.S. anti-missile battery. Seoul says the Terminal High-Altitude Area Defense (THAAD) battery is aimed at intercepting North Korean missiles, but Beijing maintains it disrupts China's military operations. The main opposition Liberty Korea Party, while not entirely denying Moon's role in resolving the THAAD issue, argues the visit did more harm than good, especially regarding national pride.The conservative LKP mostly took issue with the Chinese hosts' "mistreatment" of the South Korean leader. It cited as an example that a Chinese assistant foreign minister greeted Moon upon arrival. Beijing sent Foreign Minister Wang Yi to the airport to greet Philippine President Rodrigo Duarte last year. Wang was also on the lips of commentators here as he was seen patting the South Korean leader's arm after their handshake during the official welcoming ceremony. A conservative daily here also pointed out that President Moon "ate six meals by himself" during his stay in China."Why did President Moon visit China at all?" the Chosun Ilbo daily asked.Some Chinese officials were apparently impolite hosts at times. Nothing showed their rudeness more than Chinese security guards beating Korean photojournalists covering their president at a trade fair. The Chinese foreign ministry has promised to investigate the incident but expressed no regret or a formal apology. No decent country, particularly one that poses itself as a global leader, would have committed such a serious offense to reporters accompanying its state guests. China has a long way to go before vying with the United States for global hegemony.However, the conservative opposition party went too far when its leader described Moon's visit as "tributary diplomacy." LKP leader Hong Joon-pyo even said the South Korean leader was "given an audience" with Chinese President Xi Jinping, as the Joseon Kingdom's envoys had with the emperors of China's Ming and Qing dynasties centuries ago.I don't mind the political parties being mired in mudslinging over domestic politics. However, these politicians had better show some decency when their listeners are foreigners. Curses, like chickens, come home to roost if they use diplomatic issues for partisan interests. Throughout his trip, President Moon was seen to put national interest ahead of diplomatic protocol. Even the opposition parties should acknowledge Moon has managed to stop China's retaliatory economic sanctions for South Korea's installation of the U.S. missile shield, and has secured Beijing's agreement to the four principles for a peaceful and negotiated settlement of the North Korean nuclear issue. Moon had to clean up the diplomatic mess made by his predecessor Park Geun-hye, who deployed the THAAD battery with no prior notice to Beijing after repeatedly promising the Chinese she would not allow the battery to be deployed to Korea. A South Korean businessman reportedly expressed a tearful appreciation of the visiting president for ending the economic retaliation earlier than expected. Some conservative critics also took issue with Moon's expression of sympathy with Xi Jinping's "Chinese Dream" and his "One Belt, One Road" project while the rest of the world, particularly Washington, is suspicious of Beijing's intentions. "How can President Moon take responsibility for his words later?" one critic said.Not a few Koreans might have also felt their president was apple-polishing the host country and its leader. Flattery sometimes is part of diplomacy, however. Had similar remarks been made by Japanese Prime Minister Shinzo Abe or U.S. President Donald Trump, these critics might have described them as "pragmatism" aimed at maximizing their national interest while repressing their pride temporarily. These conservative critics praised Abe's efforts to become intimate with President Trump earlier this year as mastering his pride for his country's interests. Even Trump heaped praise on Xi during his visit to Beijing in early November, blaming past American administrations for China's yawning trade surplus with the U.S. ― to secure Xi's cooperation in defusing threats from North Korea. Smaller countries and their leaders need to be far more pragmatic than the superpowers. Supplicating the big countries only stems from their inferiority complex.Former President Lee Myung-bak, feeling a sense of crisis as prosecutors zero in on his aides for alleged corruption, criticized Moon for admitting Korea is a small country during his China visit. "Korea is not a small country," Lee reportedly told his followers Monday.The world's 14th-largest economy may not be so small, but it is much smaller than the U.S., China and Japan, which take the top three positions in the global economic rankings. Japan alone is five or six times larger than South Korea in economic size. Above all, Lee should be the last person to criticize the incumbent president because most of the diplomatic problems Seoul is now experiencing resulted from Lee's unilateral approach to Washington in near total neglect of Beijing. The CEO-turned-politician called his policy "pragmatic diplomacy" ― a complete misnomer. His was an entirely "ideological" diplomacy.South Korea can neither leave the U.S. nor abandon China. It has no choices but to continue to be pragmatic ― in its purest sense ― to survive. Choi Sung-jin is a Korea Times columnist. Contact him at choisj1955@naver.com.